Wide frequency band sampling system to test RSFQ logic

The new design of the Josephson junction based sampler has been proposed. Such a device seems to be useful for the investigating of the Single Flux Quantum (RSFQ) Logic circuits because they are based on the same junctions. The aim of this paper is to measure experimentally the time resolution of this sampler and to improve its parameters. As a delay line an array of shunted Josephson junctions have been used. The sampler is a high frequency system fed by single junction generator. The trilayer Nb-AlO x-Nb technique has been employed to fabricate tunnel junctions with critical current density 1000A/cm 2. The Josephson oscillations on the junction under investigation have been measured directly at frequencies from 2 GHz to 50GHz. The proposed sampler can be used for the experimentally measurement of the RSFQ upper frequency limit.